SRAM eTap represents yet another game changing advancement from the Chicago-based component giant. The eTap/eTap AXS system is powered by derailleur batteries- these compact, 24 gram Lithium-Ion Polymer rechargeable units. The eTap shifters are also battery powered, but use simple CR2032 coin-style versions. A single battery type is used for the two derailleurs, with a simple engagement system that holds them in place over the roughest road surfaces.

The general life span of the rechargeable eTap battery is approximately 1000km (621.4 miles), so battery management is fairly straightforward, and a good tip is that the rear derailleur is shifted more frequently, so swapping it with the front if you are running low can save the day. You will need the specific eTap Battery Charger, as well as the other necessary component items. The batteries are warrantied by SRAM for two years against material defects. Indicator lights on the respective derailleurs flash after each shift and SRAM provides the approximate battery values listed below.

Early feedback from riders indicate that SRAM's number are conservative, but with the low cost of the batteries, most eTap users have 2-4 extra and ready to go just in case, especially when traveling for race events. It is advised you always remove the batteries during bike transport, and whenever battery is not installed or on the charger the red safety cover should be used to protect the battery contacts.